#18711: fix(telegram): replace hyphens with underscores in export-session command

Telegram does not allow hyphens in bot command names. This fixes the setMyCommands failure (BOT_COMMAND_INVALID) by changing nativeName from 'export-session' to 'export_session'. Fixes #18683 <!-- greptile_comment --> <h3>Greptile Summary</h3> Changed the `nativeName` from `export-session` to `export_session` to comply with Telegram's bot command naming requirements, which only allow lowercase letters, numbers, and underscores (pattern: `^[a-z0-9_]{1,32}$`). This fixes the `BOT_COMMAND_INVALID` error when calling `setMyCommands`. - The change is consistent with other commands in the registry (e.g., `dock_${dock.id}` at src/auto-reply/commands-registry.data.ts:54) - Text aliases (`textAliases: ["/export-session", "/export"]`) correctly remain unchanged, as they can still use hyphens for user-facing commands - The fix resolves the issue where Telegram would reject the command registration due to invalid character (hyphen) in the native command name <h3>Confidence Score: 5/5</h3> - This PR is safe to merge with no risks - The change is a straightforward one-character fix (hyphen to underscore) that directly addresses a documented Telegram API requirement. The fix is consistent with existing patterns in the codebase and all text aliases remain properly functional. - No files require special attention _{Last reviewed commit: c0288f3} <!-- greptile_other_comments_section --> <!-- /greptile_comment -->